Apparatus for testing sucker rods



Feb. 7, 1933, A, M, THQMSON 1,896,114

APPARATUS FOR TESTING SUCKER RODS Filed Oct. 17. 1929 b5 INVENTORATTORNEYS l Patented Feb. 7, 1933 oil wells.

UNITED sia'ias-l PATENT orrics L man; Hemus THOMSON, oF NEWARK. NEWJERSEY, AssIeNon 'ro iuiznnmrr 'rammen conionArIoN, or NEW Yon'x, N. Y.,A CORPORATION oF-panawm APPARATUS FOB vTESTING STICKER RODS .Applicationilled October 17, 1929. Serial No. 400,262.

An importanty object of the present invention is to provide an ecientand reliable apparatus for testing the strength of sectional sucker rodssuch as arek employed in Such rods are` often extremely long and formedof a. great many rod sections separably coupled together end to end.

When one of these long rods is reciprocated in a Well bythe pumpingmachinery it is subjected to severeilongitudinal and lateral strainswhich cause it tobend or buckle at many points along its length andcause it to vibrate, and to pound and scrape against the iii .wellcasing. A severe strain istliereby imposed upon the rod couplings andfrequently causes them to unscrew orbreak. When this occurs it isextremely difficult to recover the lower length ofthe broken rod.

' The present invention provides for a thor-l ough preliminary testingof the rod sections and their couplings by subjecting said parts tostrains as nearly as possible like those of actual. service.- Theinvention further prof vides for` the performance of the test in aconvenient manner, provides for varying the severity of the testfandenables the results of the test to be readily observed. In the drawing,Fig.; 1 is a side view of the apparatus upona greatly reduced scale;

Fig. 2, a longitudinal sectional view of the apparatus upon a largerscale;

ig. 3, a. plan view of the apparatus;

Fig. 4, a longitudinal section upon a. stillk larger scale takenapproximately on the line lline -5 of Fig. 4;

- 4-4 of Fig. 2;

Fig. 5, a transverse section taken on the Fig. 6` a transverse sectiontaken on the line 6-6 of Fig.l 2; v

Fig. 7, a side view, partly in section, 0f the coupling-between a-pairofrod sections; and Fig. 8, a side view, partly in section. of one ofthe joints between the rod and the testingA I-beams lrigidly supportedhorizontally inspaced parallel relation. with their webs vertical. 'Atone end of said pair of beams isinounted a power driven mechanism 2adaptbeams and are rotatably mounted in bearings ed to be operativelyconnected to a sectional, coupled sucker rod for reciprocating itlongitudinally of the beams. Mounted at the opposite end of the pair ofbeams is a hydraulic press device y3 also adapted to be connected to thesuckerrod for `resisting its movement. Between the press device and thepower mechanism, a tubular section or cage 4 is mounted and disposed tosurround the coupling means of the sucker rod and substan- B0 tiallyduplicate the conditions under which the rod. operates when confined ina well casing. f Y

Thetpower driven mechanism 2. for reciprocating the sucker rod includesa crank 5 65 disposed between the beams and formed by a pair of spaceddisks 6 rigidly connected by a, crank pin 7 and fixed to twoshaftsections 8. The latter are disposed transversely of the 9 4supported bythe Webs of the beams. Mounted upon the upper ianges of the beams Lis anelectric motor 10 for driving the crank.

Upon the motor shaft is fixed a drive pinion 11 which meshes with a gear12 of relatively large diameter fixed to one end of a shaft 13. Thelatter is rotatably mounted'in bearings 14 mounted upon' the beams andhas a small pinion 15 'fixed to its opposite end. Pinion 15 meshes witha relatively large gearl 16 fixed upon one of the crank shaft sections8.y Thereby a reduction drive gearing is formed between the motor andthe crank. u f

The hydraulic press device 3, at the opposite end of the pair of beams,comprises a Sv pair of cylinders 17 and 18 disposed in axial alinementbetween and` along the beams and rigidly secured thereto as at 19. Saidcylin ders are spaced apart along the beams and their inner, opposed,ends are open. Be-

tween the cylinders is a combined crosshead and piston member forming acentral crosshead 20, a ram or piston 21 extending from one-end of saidcrosshead and a ram or piston 22 extending from the opposite end of thecrosshead. all integrally formed or` secured rigidly together. Ram 21 isfitted for reciprocationin cylinder 17 and ram 22 is `fitted forreeip'roeation in cylinder 18.

Between the beams 1, inwardly of the cylinder 18, is a second croeshead23 rigidly and o eratively connected to the crosshead y rods 24 whichextend past the opposite sides of said cylinder, so, that saidcrossheads and rods form in elect a single crosshead. Each head isformed for slidinl en agement with the webs and langes of t e Ieams andthe latter form guides 25 for the heads.

Two pi es 26 and 27 connect the remote, closed en s of the presscylinders 17 and 18 for exchanges of fluid therebetween. In the pipe 26is a check valve 28 located adjacent the cylinder 17 and a manuallyoperable needle valve 29 located adjacent the cylinder 18.

Said check valve opens away from cylinderl 17. In pipe 27 is a checkvalve 30 located adjacent the cylinder 18 and a manually operable needlevalve 31 located adjacent cylinder 17 Check valve 30 opens away fromcylinder 18. A pressure gauge 32 has a pipe connection with the closed'end of cylinder 17 and a pressure gauge 33 has a pipe connection withthe closed end of cylinder 18.

Connected to the crosshead 23 are pullback means to assist in moving theconnected rams and crossheads in a direction away from the crank. `Thismeans includes two arms 34 which extend laterally from opgesite sides ofthe crosshead 23 and outwar ly through clearance slots 35 in the beamwebs. Two pulleys 36 are mounted upon outwardly extending arms 37supported by the beams land spaced outwardly therealong from the arms34. Secured to the latter and trained over the pulleys are cables 38from which weights 39 are suspended. The weights tend to move the ramsand crossheads to the'left, with reference to the drawing.

A form of sucker rod which the apparatus is designed to test isindicated at R. Such a rod is usually made in sections S each aboutthirty feet in length. Each section is formed with threaded ends 40, andthe opposed ends' of two successive sections are threaded into acoupling member C. Thel latter is formed with` threaded sockets 41 atits opposite ends to receive the ends of the rod sections, and is formedwith a reduced and flattened `medialportion adapted to be engaged by a`wrench. The sections are formed with simi-- lar wrench engaging portionsand areformed ,also with enlarged heads 42 at the roots of .bercomprises a split sectional strap 44 which defines an eye for encirclingand pivotally engaging the crank pin 17 and has its sections securedtogether by bolts.

sion 45 into which one of the threaded ends 40 of the rod is adapted tobe screwed. An-

other coupling member 46 is rigidly secured One sec- 'tion rigidlycarries a threaded socket extento the crosshead 23 and is in the form ofa threaded socket member similar to the socket extension 45 and adaptedto have the opposite end of the rod R threaded into it.

The cage 4, in the present instance, is inthe form of a straight.tubular metal section so proportioned and disposed between the L beamsas to surround the coupling C between the rod sections, when the rod isconnected into the apparatus, and to substantially duplicate theconditions under which the coupling will have to work when confined in awellcasing in actual service.

In the operation of the apparatus a length of sucker rod formed by aplurality of coupled sections is extended through the cage 4 and itsopposite threaded ends 40 are screwed into the sockets 45 and 46 of thecrank and the hydraulic device respectively.

Between said sockets the rod is entirely unsupported so that it is freeto ilex and move laterally in any direction to a limited extent. Anapproximately correct adjustment of the needle valves 29 and 31 is madeand the motor 10 is started, for rotating the crank rod, and theadjustment is made in accordance with the length and strength of therod.-

In the drawing, a rod composed of only A two sections is shown undertest. The apparatus may, however, be pro rtioned to accommodate a longerrod. slender rod is of course much stron er under tension than undercgtxpreion. erefore the valve 81 is adju to materially restrict the flowfrom cylinder 18 to cylinder 17 and cause a strong resistance incylinder 18 to the movement of the crosshead structure to the right. ortoward the crank. Con uentl `the rod R is placed under strong tension.alve 29, on the contrary, is opened much wider than valve 31 so that thereverse flow from cylinder 17 to cylinder 18 is much less restricted.

and less resistance is offered to the movement of the crossheads and therod R toward the left. Gauge 32 indicates the hydraulic resistance tothe thrust of the rod and gauge 33 indicates the pull resistance imposedupon the rod. If the rod is found to be too long or too weak underthrust to push the crosshead and ram structure, with a given restrictionin the valve 29, the latter is opened wider and the pull-back weights 39operate to assist the movement. Each weight preferably has a pluralityof removable sections, as indicated, so that the weights may be variedto suit different r uirements.

Oil wel s are commonly very deep and very crooked and when a lon suckerrod is reciprocated in such a well 1t is caused to sway, flex andgyrate. Upon its downward stroke it is buckled and upon its upwardstroke the bending and straightening of the' rod imposes a particularlysevere strain upon the couplings, causing them tonnscrew or break.v Thepresent apparatus provides for a substantial duplication of thesestrains in a preliminary test so that any kweaknessin the rod sectionsand their couplings can be de- '.tected before the rod is put intoservice. By

' the motor,

` the rod and frictionally cfnacts it in much.

proper adjustment of the valves and by operating the apparatus at theproper rate by through the reduction gearing, the actual pull an thrustconditions can be established as they exist in service. By changing thevalve adjustments the severity of the test may be variedcorresponding tothe strains in wells of different depths. .Observance of the lgauges 32and 33 and of the duration of the test and the number of strokes of therod will indicate the severity 'of the test.

The tubular cage 4 limi'I the buckling of the same manner as a wellcasing. The internal diameter of the tube is roperly chosen withreference to the throw ofpthe drive crank 5 to reproduce the naturalconditions. A tube or cage of any suitable length may be used. If therod is found to buckle beyond the ends of the tube, said bucklingmay belimited or confined to a normal degree by merely placin heavy metal bars47 across the beams at t e necessary points and in the required number.This amounts in effect to a lengthening of the cage withoutobjectionably obscuring the rod or obstructing its insertion andremoval.

While I have shown and described a very satisfactory form of myinvention and a particularly advantageous use thereof I do not wish tobe limited strictly to this disclosure but reserve the right to makesuch changes in the structure and use of the apparatus as will liewithin the scope of the claims.

lVhat I claim is:

1. An apparatus for testing the couplings of sectional-sucker rods,comprising a rotat- -ably mounted crank; a crosshead; guides for saidcrosshead rigidly mounted in fixed relation to the crank axis at amaterial distance from the latter, and supporting the crosshead forreciprocation toward and from said axis; means to connect one end of asectional 'coupled rod operatively and detachably to the crank; means toconnect the opposite end of said roddetachably tothe crosshead; atubular section mounted between the crank and the crosshead to surroundthe coupling means between the rod sections, the interna! diameter ofsaid tubular section being substantially the same as vthat `of a wellcasing inwhich the rod is to be used; power means for rotating the crankand reciprocating the crosshead through the medium of the connected rod;and means for resisting movement of the crosshead and imposing -a loadAupon the-rod and its coupling means.

2. An apparatus for testing' a long rod formed of coupled sections,comprising a rotatably mounted crank; guides for said crosshead rigidlymounted 1n fixed relation to the crank axis at a material distance fromthe latter, and supportingthe crosshead for reciprocation toward andfrom said axis; means to connect one end of a sectional coupled rodoperatively andldetachably to the crank; means to connect the oppositeend of said rod detachably to the crosshead; a cage mounted between thecrank and the crosshead to surround the coupling means between the rodsections and limit buckling of the rod; power means for rotating thecrank and reciprocating the crosshead through the medium of theconnected rod; and means for resisting movement of the crosshead andimposing a load upon the rod and its coupling means.

3. An apparatus for testing the couplings of sectional sucker rods,comprising a rotatably mounted crank; a crosshead; guides for saidcrosshead rigidly mounted in fixed relation to the crank axis at amaterial distance a crosshead; t'

from the latter, and supporting the crosshead for reciprocation towardand from said axis; means to connect one end of a sectional coupled rodoperatively and detachably to the crank; means to connect the oppositeend of said rod detachably to the crosshead; a

'tubular section mounted between the crank and the crosshead to surroundthe coupling means between the rod sections, the internal diameter ofsaid tubular section being substantially the same as that of a wellcasing in which the rod is to be used; power means for rotating thecrank and reciprocating the crosshead through the medium of theconnectedrod; means for resisting movement of the crosshead and imposing a loadupon the rod and its coupling means; and adjustable means to vary saidcrosshead resistance.Vv

4. An apparatus for testing the couplings of sectional sucker rods,comprising a rotatably mounted crank; a crosshead; guides for saidcrosshead rigidly mounted in fixed relation to the crank axis at a.material distance from the latter, and supporting the crosshead forreciproeation toward and from said axis: means to connect one end of asectional coupled rod operatively and detachablyto the crank; means toconnect the opposite end through the medium of the connected rod;

means for yicldingly resisting the reciprocation of .the crosshead andthereby imposing a push load and a pull load alternately upon the rod;and adjustable means for varying said push load and pull loadindependently of each other.

An apparatus for testing sectional sucker rods` comprising apower-operated means adapted to be connected to one end'of a sectionalsucker rod to apply a push-andpull force thereto to reciprocate saidrod; a reciprocable device adapted to be connected to the other end ofsaid' sucker rod; means to conenct one end of a sectional coupled rodoperatively and detachably to said poweroperated means; means to connectthe other end of said rod to the said reciprocable device; a cagebetween said power-operated means and said reciprocable device tosurround the coupling between the rod sections and permit limitedlateral deection of the coupling in any direction within the cage; meansfor yicldingly resisting movement of the rcciprocahle device in bothdirections and imposing a push load and a pull load alternately on thcrod to alternately flex and straighten said rod; and adjustable meansfor varying said push load and pull load independently of each other.

6. An apparatus for testing sectional suckerl rods, comprising apower-operated means adapted to be connected to one end of a sectionalsucker rod to apply a push-andpull force thereto to reciprocate saidrod; a rcciprocable device adapted to be connected to the other end ofsaid suckerrod; means to connect one end of a sectional coupled rodoperatively and detachably to said poweroperated means; means to connectthe other end of said rod to the said reciprocable device; a cagebetween said power-operated means and said ieciprocabe device tosurround the coupling between the rod sections` and permit limitedlateral deflection of the coupling in any direction within the cage;

and means for yieldingly resisting movement of the reciprocable -devicein both directions and thereby imposing a push load and a pull loadalternately on the rod'to alternately flex and straighten said rod.

T. An apparatus for testing sectional sucker rods. comprising apower-operated means adapted to be connected to one end of a sectionalsucker rod to apply a push-andpull torce thereto to reciprocate saidrod; a rociprocablo device adapted to be connected to the other ond ofsaid sucker rod; means lo connect on:- ond of a `sectional coupled rodcou ling between the rod sections and permit limited lateral deflectionof the coupling within the cage; means for yieldin ly resisting movementof the reci rocable evice and.

thereby imposing a .loa on the rod; .and adjustable means for varyingsaid load.

8. An apparatus for testing the couplings of sectional sucker rods,comprising a rotatably mounted crank; a crosshead; ides for saidcrosshead rigidly mounted in ed rela.- tion to the crank axis at amaterial distance from the latter, and supporting the crosshead forreciprocation toward and from said axis; means to connect one end of asectional coupledrod operatively and detachably to the crank; means vtoconnect the opposite end of said rod detachably to the crosshead; atubular section mounted between the crank and the crosshead to surroundthe couplin means between the rod sections, the intern diameter of saidtubular section being substantially the same as that of a well casing inwhich the rod is to be used; power means for rotating the crank andreciprocating the Y crosshead through the medium of the connected rod;hydraulic means foreres'isting movement of the crosshead and imposinv a.load. upon the rod; and valve means or varying said resistance.

9. An apparatus 'for testing the couplings of sectional sucker rods,comprising a pair of elongated beams supported in spaced parallelrelation; a crank supported by said beams and mounted for rotationtherebetween; a crosshead; guides for said crosshead carried by saidbeams and supporting the crosshead for longitudinal reciprocationbetween the beams toward and from the crank axis, said guides beingspaced a material distance along the beams from the crank; means toconnect one end of a sectional, coupled rod operatively and detachablyto the crank; means to connect the opposite end of said rod detachablytothe crosshead; a tubulai` section extending longitudinally between thebeams in a' position between the crank and the crosshead to surround thecoupling means between the rod sections, the internal diameter of saidtubular section being substantially equal to that of a well casing inwhich the rod is to be used; means for rotating the crank andreciprocating the crosshead through the medium of the connccted rod;means supported by the beams for resisting movement of the crosshead andimposing a load upon the rod; andadjustable means for varying saidcrosshead resistance, whereby the effects of lateral deflection of therod under a given load and of the Aconsequent frictional contact of thecoupling means with the interior of said tubular section may bedetermined.'

10. An apparatus for testing the couplings of sectional sucker rods,comprising mechanical means to detachably engage one end of a sectionalcoupled rod and impart a longitudinal andlateral movement to the rodsimilar to its normal operating movement in a well; a tubular sectionsupported in a position to surround the coupling means between the rodsections and having an internal diameter corresponding substantially tothat of a well casing in which the rod is to be used; means to impose alongitudinal stress upon the rod as itis moved; and adjustable means tovary said stress, whereby the effects of lateral deflection of the rodunder a given stress and of the consequent frictional contact of thecouling means with the interior of said tubuar section may bedetermined. l 11. An a paratus for testing an elongated rod forme ofcoupled sections, comprlsing mechanical means to detachably engage oneend of said rod and reciprocate it longitudinally; a tubular cage tosurround the coupling means between the rod sections and limit bucklinof the rod; means to impose a longitudina stress upon the rod; andadjustable means to vary said stress, whereby the effects of lateraldeflection of the rod under a given stress and of the consequentfrictional contact of the coupling means with the interior of said cagemay be determined. 12. An apparatus for testing a long rod formed ofkcoupled sections,com rising power operated means adapted to connectedto one end of said rod to apply push and pull force to the rod toreciprocate it; a reciprocable device adapted to be connected to theother end of the rod; a cage between said ower operated means and saidreciprocable device to surround the coupling between the rod sectionsvand permit limited lexure of the rod within the cage; and a mechanismfor resisting movement of the reciprocable device in both directionscomprising a pair of hydraulic cylinders, plungers in said cylinders,restricted fluid conduit means between the cylinders, and an operativeconnection between said reciprocable device and said plungers forshifting the latter to force fluid back and forth from one cylinder tothe other as said reciprocable device is reciprocated. l

13. An apparatus for testing a long rod formed-of coupled sections,comprising power operated'means adapted to .be connected to one endof'said rod to applypush and pull force' to the rod to reciprocate'it; areciprocable device adapted to be connected to the other end-of the rod;a cage beween said power operated means and said reciprocable device tosurround the coupling'between the rod sections and permit limitedflexure of the rod within the cage; a mechanism for resistbothdirections comprising a ing movement of the reciprocable device indraulic cylinders, plungers. in said cylinders, restricted fluid conduitm'eansbetween the cylinders, and an operative connection betweensaidrleciprocable device andlsaid plungers for shifting the latter toforce fluid back and forth from one cylinder to the other as said deviceis reciprocated; 'and adjustable means to independently vary the flow offluid in opposite directions from one cylinder to the other and'Vthereby independently vary the push and pull resistance to the move-Vment of the rod.

14. Anapparatus for testing a long rod formed of coupled sections,comprising power operated means adapted to be connected to one end ofsaid rod to apply push and pull force to the rod to reciprocate it; areciprocable device adapted to be connected to the other end of the rod;a cage between said power operated means and said reciprocable device tosurround the coupling between the rod sections and permit limitedflexure of the rod within the cage; means for resistin movement of thereciprocable device in bot directions comprising a pair of hydrauliccylinders plungers in said cylinders, yrestricted fluid conduit meansbetween the cylinders, and an operative connection between saidreciprocable means and said plungers for shifting the latter to forcefluid back and forth from one cylinder to the other as said device isreciprocated; and gauges to indicate the Huid pressures Vin thecylinders.

15. An apparatus for testing a long rod formed of coupled sections,comprising power operated means adapted to be connected to one end ofsaid rod to apply push and pull force to the rod to reciprocate it; areciprocable device adapted to be connected to the other end of the rod;a cage between said power operated means and said reciprocable device tosurround the coupling between the rod sections and permit limitedflexure of the rod within the cage; a hydraulic mechanism for resistingmoveinentof the reciprocable device in both directions; and means toautomatically assist the movement of the reci rocable device in onedirection and there y reduce thrust stressY upon the rod.

16. An apparatus for testing sectional sucker rods, comprising apower-operated means adapted to bel connected to one end of a sectionalsucker rod to apply a push-andpull force thereto to reciprocate saidrod; a reciprocable device adapted to be connected to the other end ofsaid sucker rod; means t0 connect one end of a sectional cou led rodoperatively and detachably to sai poweroperated means; threaded couplingmeans,to connect the other end or said rod to the said reciprocabledevice; a cage between said power-operated means and said reciprocabledevice to surround the coupling between the pair of hyrod sections andpermit limited flexure of the rod Within the cage and meansfor yielding'ly resisting movement of the reciprocable device and thereby imposing aload on the rod.

17. An apparatus for testing sectional sucker rods, Vcomprising apower-operated means adapted to be connected to one end of a sectionaisucker rod to apply a pushand-pull force thereto to reciprocate saidrod; a rcciprocabe device adapted to be connected to the other end ofsaid sucker rod; means to connect one end of a sectional coupled rodoperatively and detachably to said power-operated means: means todetachably connect the other end oi .zaid rod to the said reciprocabledevice; a cage between said uwer-operated means and said reciprocabledevice to surround the coupling between the rod sections and permitlimited lateral deiection of the coupling Within the cage; and ahydraulic mechanism for resisting movement of the reciprocable deviceand thereby imposing a longitudinal stress upon the rod.

18. An apparatus for testing a rod formed of coupled sections comprisingmechanical means connectable to one end of said rod to applylongitudinal push and pull force thereto; means connectable to theopposite end of the rod to resist longitudinal movement thereof by saidmechanical means and cause the rod to buckle under the push force; and acage to surround the rod coupling and limit buckling of the rod. y

ln testimony Wlie-e0f I hereunto aiiX my signature.

ALFRED MORRIS THOMSGN.

